Esophageal achalasia, or simply achalasia, is an esophageal motility disorder. The smooth muscle of the esophagus and the circular muscle located at the junction between the stomach and esophagus, called lower esophageal sphincter, are involved. Primary esophageal achalasia does not have any known underlying cause, but some cases are attributed to Chagas’ disease and esophageal cancer. The most common symptom is difficulty in swallowing, or dysphagia. Although several treatments for the symptoms are available, there is no proven cure for this condition.
When food travels down from the mouth through the esophagus and then into the stomach, the lower esophageal sphincter (LES) relaxes to allow smooth passage. In esophageal achalasia, passage is impeded because the LES has increased muscle tone and does not completely relax. Additionally, the smooth muscle of the esophagus is unable to push down the food toward the stomach, a condition known as aperistalsis. Both of these mechanisms are attributed to the failure of esophageal inhibitory neurons to fire in response to swallowing stimuli. As a result, an affected person experiences swallowing difficulties.
The difficulty in swallowing caused by achalasia is usually progressive. Initially, an affected person only unable to swallow solids, but over time even fluids present a swallowing challenge. Another common symptom of esophageal achalasia is regurgitation of undigested food, which frequently occurs when a person is lying down. Regurgitation increases the risk of aspiration, which could lead to pneumonia. Many patients also experience chest pain or heartburn, usually during mealtime, and this symptom explains why esophageal achalasia is also called achalasia cardiae or cardiospasm.
Diagnosis of esophageal achalasia is sometimes difficult because its symptoms are similar to gastroesophageal reflux, hiatal hernia, and other functional disorders. Therefore, the physician usually requests a series of tests including barium swallow, esophageal manometry, endoscopy, endoscopic ultrasound, and computed tomography (CT) of the gastroesophageal junction. The latter three tests are important in striking out gastroesophageal malignancy from the possible diagnosis. A barium swallow is a procedure wherein achalasia is indicated by a “bird beak” narrowing of the gastroesophageal junction. In manometry, findings that point to achalasia include both esophageal aperistalsis and increased or normal LES tone that fails to relax completely on swallowing.
Treatment of esophageal achalasia involves drugs that reduce the LES tone, changes in lifestyle, pneumatic dilatation, and surgical interventions. The first-line treatment for esophageal achalasia is pneumatic dilatation, an intervention that involves the placement of a balloon in the LES. Botulinum toxin injection and nifedipine intake can help reduce LES pressure. Avoidance of eating near bedtime and consuming both alcohol and caffeinated products is also recommended.
If these interventions do not work, a surgical procedure called Heller myotomy may be performed. It involves cutting along the esophagus, starting from the LES and down to the proximal part of the stomach. In this procedure, the cut only involves the outer layers of the esophagus. Fundoplication, or “wrapping” the part of the stomach called fundus around the distal esophagus, is performed to minimize acid reflux.